I like to play. I like the pay. As I tell people who ask, I'm not getting paid to play. I'm getting paid to practice, learn songs, have working gear, load in and load out, be away from my family, etc. That said, there are times when I play for very little pay. It may be a genre that isn't super popular or doesn't command large crowds to get the pay. Background jazz gigs at socials for example. I might get $50-$100 for an hour or two. I play with a singer/songwriter couple (they play acoustics) that does covers and originals. Again, I might make $50-$100 for an hour or two. My church gig is $75 a Sunday for two services. The cover band where I play bass and bass synth is much more work with sound and lights to load in and set up. It's about a 2 hour load in/soundcheck and about an hour for load out. Mostly 3 hour gigs. We usually get $300-$500 a gig.
I don't "need" the money, but it sure helps for maintaining gear, and to have some "gravy" money for the kids' needs which are more expensive as they age. Cars, apartments, instruments, etc. I am careful about playing for "beer" as I real it devalues what most musicians/bands do. I wouldn't do the cover band gig for free, but with a tip jar to pull from I'd probably do the others for free or "beer" as there's very little pre or post work, not a lot of venues, and its a nice variety of music.